Simple way to mark a sprocket tooth.

[gearoidmuar]

I've a 40 x 16 system which gives you an even number of teeth in both. If you keep these in phase after you remove the wheel and put it back, it apparently gives a wear advantage. If not, and you haven't changed the wheel for a long time, it's noisy.
I've marked the chainwheel by making a small mark on the chainguard, which I have, corresponding to a tooth with a narrow link.
I used to clean one tooth on the back and use this as a guide, but this was a bit finicky and I've thought of a better way.
Mark the circle under the relevant tooth by wedging something into it. In this case a small circle of plastic from some kind of electrical plastic thing I found lying around. Anything that would last would do.
See picture.

[Hamish]

I have been wondering whether it is better to use sprockets and chainrings with odd numbers of teeth?

My setup is very worn now and it is time to change the drive train.  Should I go odd ti avoid this problem?  Are there any disadvantages?

[gearoidmuar]

I've thought of doing that myself, but I've read an article on line by the late lamented Sheldon Brown and he implied that there was a wear advantage to the even even setup if you kept it in phase. I've a spare 16 sprocket, so I think I'll wear that out too before I change. It's easy sometimes to throw good money after bad!

[sg37409]

This post made me wonder if this was why my silent drive became noisy after the chain came off. (I have a 40*16 setup)
I surfed sheldon,  found this  and am convinced thats what happened.

I replaced the chain at the weekend and its silent again, but I should also turn the sprocket round too as I can feel it not quite perfectly smooth.